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Shot Peening Discussion
I thought some might be interested in learning a bit about shot peening.
Shot peening is a process where the part is blasted with steel balls (shot) to form small dents in a uniform maner on the part surface.
Shot peened parts are not stronger* than non-peened parts. The advantage of shot peening is increased fatigue life**.
By battering the surface with steel shot, the top .005-.030' of the surface is compacted creating a compressive layer of material.
The compressive layer is important because a crack will only grow if it is pulled apart (put in tension). If a cracked material is only pushed together (loaded in compression) the crack will never grow.
Cracks almost always initiate on the surface of parts. The compressive surface layer will go a long way to preventing these cracks from forming and growing.
I thought some might be interested in learning a bit about shot peening.
Shot peening is a process where the part is blasted with steel balls (shot) to form small dents in a uniform maner on the part surface.
Shot peened parts are not stronger* than non-peened parts. The advantage of shot peening is increased fatigue life**.
By battering the surface with steel shot, the top .005-.030' of the surface is compacted creating a compressive layer of material.
The compressive layer is important because a crack will only grow if it is pulled apart (put in tension). If a cracked material is only pushed together (loaded in compression) the crack will never grow.
Cracks almost always initiate on the surface of parts. The compressive surface layer will go a long way to preventing these cracks from forming and growing.
*Strength is how much load you can put on a part before it deforms excessively or breaks. Example: pull on a piece of wire until it breaks into two pieces.
**Fatigue life is how many times you can repeat a loading cycle before the part will crack and fail. Example: bend a piece of wire back and forth until it breaks at the bend.
**Fatigue life is how many times you can repeat a loading cycle before the part will crack and fail. Example: bend a piece of wire back and forth until it breaks at the bend.